Abstract Non-invasive prenatal testing (NIPT), a cell-free DNA screening test of fetal chromosomal abnormalities using maternal plasma, has been heralded as ?revolutionizing prenatal screening and diagnosis.? Introduced commercially in late 2011, the rapid clinical adoption of NIPT highlights genomic medicine?s growth and enormous promise for patient care. The research landscape stemming from genomic and precision medicine endeavors, however, necessitates concomitant efforts to monitor population health impact and assure equity in access to these advances. Although genomic discovery has accelerated at a rapid pace, the corresponding rate of research examining the effectiveness of genomics translation into clinical or public health practice has lagged behind. It has been estimated that over 100,000 NIPTs have been performed in the United States as of 2014. Yet, the literature to date on the adoption of NIPT is from convenience samples from single clinic settings. Currently, there is a glaring paucity of population-based evidence on utilization of and patient benefits from NIPT. The existing evidence base is not sufficient to draw a clear picture of the population-level trends in NIPT adoption, particularly among vulnerable subpopulations by socioeconomic status, race/ethnicity, and insurance coverage. As such, there is no information on the extent of inequities in NIPT use and impact. Using a uniquely comprehensive healthcare database covering all Massachusetts residents aged 18-64, we propose to measure documented NIPT use and gains realized from reduction of conventional invasive diagnostic testing among the overall population and across diverse subpopulations by socioeconomic status (SES), race/ ethnicity, and insurance coverage. The database captures the entire spectrum of maternity care covering prenatal visits, NIPT, genetic counseling, chorionic villus sampling and amniocentesis. The specific aims of this study are to 1) estimate annual population rate of use of NIPT during 2012-2015 among all pregnant women and among subgroups based on maternal age, SES, race/ethnicity and insurance; 2) develop a person-level model to identify the multilevel factors associated with NIPT uptake (i.e., patient, provider, hospital and geographic area), and examine the extent to which the model accounts for disparities in NIPT uptake by SES, race/ethnicity and insurance; and 3) examine the association between NIPT adoption and use of invasive diagnostic testing, and variation in this association by SES, race/ethnicity and insurance. The proposed study will generate population-based evidence that will inform a range of stakeholders ? pregnant women, providers, professional societies, payers, and state policymakers ? on the extent to which anticipated benefits of NIPT have been realized across different subpopulations, and identify potential barriers and facilitators to address inequities that may be arising from the introduction of NIPT. Findings will be important for evaluation of new advances in genomic medicine based on equity in accessibility and patient impact.